Centering means and method of forming monolithic arches



W. M. BELT kAND H. C. SMITH.

CENTERING MEANS AND ME.THOD 0E FORMING MONOLITHIC ARCHES.

APPLICATION FILED EEB. 2l, I9I7.

1,350,772. PatentedAug.24,1920.

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i bm p i N L., f. .D .N @YQ P w UNITED STATES PATENT. OFFICE.

WILLIAM M. BELT AND HERSOHEL C. SMITH, OF BLOOMINGTON, ILLINOIS, ASSIGNORS,

BY MESNE ASSIGNMENTS, TO AMERICAN CONCRETE FOR-MS COMPANY, OF BLOOM- INGTON, ILLINOIS, A CORPORATION OF ILLINOIS.

CENTERING MEANS A ND METHOD OF FORMING MONOLITHIC ARCHES.

Application filed February 21, 1917.

To all whom t may concern:

Be it known that we, IVILLIAM M. BELT and Hanser-inn C. SMITH, citizens of the United States, and residing at Bloomington, in the county of McLean and State of Illinois, have invented certain new and use-. ful Improvements in @entering Means and Methods of Forming Monolithic Arches, of which the following is a specification.

In a co-pending application, filed February 17, 1917, Serial No.-11l9,162, a mechanism and method has been disclosed for molding arch ribs to be used in combination with precast reinforced concrete slabs, to build up a concrete arch. IVhile the method disclosed in the co-pending application has many advantages, it may sometimes be desired where the essential advantages of the precast slab idea are not important, (as, for instance, where there is no great hurry to put the bridge in use, or where the materials for concrete constructions are easily available, and do not have to be shipped long distances,) to make a monolithic construction. To provide for this contingency, we have developed the invention herein disclosed, in'which a mechanism, somewhat similar to that involved in the application referred to is employed but wherein by addition thereto it is possible to make the arch monolithic.

In the drawings:

Figure 1 is an elevation of a portion of the rib centering frame.

Fig. 2 is a cross sectional view of a portion of an arch rib constructed according to our invention.

Fig. 3 is a sectional view of a modification of the invention.

The arch rib centering has side pieces 11 adjustably connected by links 12, to form a rib centering of any required span and rise, according to where the bolts 13 are set into the holes 14 in the reinforcing frames 15, as more fully described in the co-pending application. The side pieces 1l are bent over at their tops as indicated at 16, and are secured to the bottoms 17 for molding the bottoms of the arch ribs.

Instead of using reinforced concrete slabs resting upon the tops 16 of adjacent side pieces 11, and forming molds for the sides of the arch ribs, this invention. contemplates the use of special centering 18 of Specification of Letters Patent.

Patented Aug'. 24, 1920.

Serial No. 149,993.

boards or the like, resting upon adjacent tops 16 of the side pieces 11 of successive preferably they project over to an extentsufficient to permit a i'irm support and the blocks 19 are used.

In Fig. 3 a modification of the invention is shown, wherein the inner surface of the barrel of the arch is made perfectly smooth, as is sometimes desirable lto avoid transverse obstructions, which catch rubbish, etc., in the event of floods. In this modification the center boards 18 are laid entirely across the rib centering construction, or abutted at the center of the rib centering of the construction, blocks 19 being used, which completely fill up the top portion of the rib centering, each of which is attached to an end of the two abutting boards. In this construction, the entire inside of the barrel of the arch is sheathed with boards so that a perfectly smooth surface is produced.

After the arch has been constructed and thercentering frames removed, the boards 1S are removed, leaving a solid monolithic arch.

In the event that it is not desired to have the ribs project below 'the under surface of the arch. the boards-1 may be laid all the way across the rib centerings as indicated in Fig. 3.

Having now described our invention, we claim 1. In a monolithic concrete arch construction in combination a plurality of narrow rib forming centering frames adjustable for rise and span, and easily removable teinporary centering elementsl spanning adjacent rib-forming centering frames to form molds for the barrel of the arch between said ril centerings.

2. In monolithic concrete arch eonstruc tion in combination a plurality of spaced adjustable narrow centering frames having means to the rib only, and a plurality of centering elements spanning adjacent rib centering frames to form molds for the under Surface of the barrel of the arch.

3. In monolithic concrete arch construction in combination a plurality of spaced adjustable arch rib centerings having side portions to mold the sides of the portion of the ribs projectingl below the barrel of the arch, and removable temporary supports resting at either end upon the Vadjacent vertical sides of successive rib centerings, whereby to form a mold for the bottoni of thebarrel of the arch.l

4L. In monolithic concrete arch construction in combination a plurality of arch rib centerings each comprising series of connected mold sections having means to form a mold for the rib only, said connected mold sections having means for adjusting the rise and span of the rib centerings respectively and removable Atemporary supports resting at either end upon the adjacent sides of the rib centerings whereby to form a mold for thebottom of the barrel oi the arch.

5. The method of forming a monolithic concrete arch which consists' in setting up adjustable spaced arch rib-forming centering frames, adjusting' said trames to give the desired span and rise, laying boards or Athe, like between and upon adjacent rib centerings to form a mold for the barrel oit' the arch, pouring concrete upon the top of the completed mold thus formed, allowing the concrete to harden, and subsequently removing the rib centerings and Vboards or the like, substantially as described.

6. In a monolithic concrete arch construction in combination, a plurality or spaced apart centering trames adjustable for rise and span and each having upwardly projecting side edges and a depressed bottom to provide a rib forming mold, and removable mold boards spanning the space between said spaced apart frames, said boards resting with their ends on said side edges whereby when concrete is poured thereon, the boards will form the barrel of the arch and the frames will form projecting ribs.

In witness whereof, we hereunto subscribe our names to this specilication in the presence of two witnesses.

. VILLIAM M. BELT. HERSCHEL C. SMTH.

vWitnesses:

SEBASTIAN HI-NTON, C. I. SHERMAN. 

